Fibers having electrically conductive core and color-changing coating

Abstract

A method of manufacturing a color-changing fiber includes loading a polymeric material and a thermochromic pigment material into a fiber fabrication machine that comprises an extruder and a spinneret, operating the extruder to provide a molten mixture of the polymeric material and the thermochromic pigment material, providing a volume of the molten mixture to the spinneret, and operating the spinneret to coat an electrically conductive core with the molten mixture to form a coating layer around the electrically conductive core to produce the color-changing fiber. The polymeric material and the thermochromic pigment material are provided as (a) a first raw material comprising the polymeric material and a second raw material comprising the thermochromic pigment material or (b) a thermochromic pigment and polymer mixture.

The invention claimed is: 
     
       1. A method of manufacturing a color-changing fiber product, the method comprising:
 coating an electrically conductive core with a first molten mixture to form an inner coating layer around the electrically conductive core to produce a color-changing fiber; and 
 coating the color-changing fiber with a different molten mixture to form an outer coating layer over the inner coating layer; 
 wherein the outer coating layer is configured to activate at a first temperature threshold and the inner coating layer is configured to activate at a second temperature threshold that is higher than the first temperature threshold; 
 wherein a first temperature at or above the first temperature threshold is configured to cause the outer layer to transition from an opaque state to an at least partially transparent state to expose the inner coating layer; and 
 wherein a second temperature at or above the second temperature threshold is configured to cause the inner coating layer to transition from a first opaque state to at least one of a second, different opaque state or a third, at least partially transparent state. 
 
     
     
       2. The method of  claim 1 , further comprising:
 loading a polymeric material and a first thermochromic pigment material into a fiber fabrication machine that comprises an extruder, a melt pump, and a spinneret, wherein the polymeric material and the first thermochromic pigment material are provided as (a) a first raw material comprising the polymeric material and a second raw material comprising the first thermochromic pigment material or (b) a thermochromic pigment and polymer mixture; 
 operating the extruder to provide the first molten mixture of the polymeric material and the first thermochromic pigment material to the melt pump; 
 providing a volume of the first molten mixture to the spinneret with the melt pump; 
 operating the spinneret to collapse the first molten mixture onto the electrically conductive core as the electrically conductive core moves through a housing of the spinneret to coat the electrically conductive core with the first molten mixture to form the inner coating layer around the electrically conductive core to produce the color-changing fiber. 
 
     
     
       3. The method of  claim 2 , wherein the fiber fabrication machine includes a single hopper and a single extruder that receive the polymeric material and the first thermochromic pigment material. 
     
     
       4. The method of  claim 2 , further comprising at least one of:
 (i) controlling the volume of the first molten mixture provided to the spinneret to provide the inner coating layer on the electrically conductive core with a desired thickness; 
 (ii) controlling a speed at which the electrically conductive core is driven through the spinneret to provide the inner coating layer on the electrically conductive core with the desired thickness; 
 (iii) quenching the color-changing fiber after coating the electrically conductive core with the first molten mixture; or 
 (iv) winding the color-changing fiber onto a spool. 
 
     
     
       5. The method of  claim 2 , wherein the electrically conductive core is a prefabricated wire, and the method further comprises providing the prefabricated wire to the spinneret and feeding the prefabricated wire through the housing of the spinneret. 
     
     
       6. The method of  claim 2 , wherein the fiber fabrication machine includes a core delivery system, and the method further comprises:
 loading the core delivery system with raw core materials; 
 operating the core delivery system to (i) melt the raw core materials into molten core materials and (ii) provide the molten core materials to the spinneret, wherein the spinneret is a bicomponent melt extrusion pack configured to co-extrude the molten core materials and the first molten mixture in the form of the color-changing fiber; and 
 operating the spinneret to generate the electrically conductive core within the housing of the spinneret from the molten core materials and collapse the first molten mixture onto the electrically conductive core formed from the molten core materials as the electrically conductive core moves through the housing. 
 
     
     
       7. The method of  claim 2 , wherein the fiber fabrication machine includes (i) a first hopper and a first extruder that receive the polymeric material and (ii) a second hopper and a second extruder that receive the first thermochromic pigment material. 
     
     
       8. The method of  claim 1 , wherein the electrically conductive core comprises a metallic or non-metallic electrically conductive material. 
     
     
       9. The method of  claim 1 , further comprising braiding the color-changing fiber with a second fiber to provide a color-changing yarn. 
     
     
       10. The method of  claim 9 , wherein the second fiber is the same as the color-changing fiber. 
     
     
       11. The method of  claim 9 , wherein the second fiber is a non-color-changing fiber including at least one of a natural fiber, a synthetic fiber, or a photovoltaic fiber. 
     
     
       12. The method of  claim 9 , wherein the second fiber includes a third coating layer that at least one of has a different thermochromic pigment material or has a different polymeric material than the inner coating layer or the outer coating layer of the color-changing fiber. 
     
     
       13. The method of  claim 1 , further comprising:
 (i) weaving or knitting the color-changing fiber to form at least a portion of a fabric; 
 (ii) embroidering the color-changing fiber into a pre-existing fabric; or 
 (iii) arranging the color-changing fiber into a patch and coupling the patch to the pre-existing fabric. 
 
     
     
       14. The method of  claim 13 , wherein the patch includes a first patch and a second patch, wherein the first patch is configured to be controllable to transition the first patch from displaying a first word to a second, different word, and wherein the second patch is configured to be controllable to transition the second patch from displaying a first number to a second, different number. 
     
     
       15. A method of manufacturing a color-changing product, the method comprising:
 manufacturing a plurality of color-changing fibers including:
 loading a polymeric material and a thermochromic pigment material into a fiber fabrication machine that includes an extruder, a melt pump, and a spinneret; 
 operating the extruder to provide a first molten mixture of the polymeric material and the thermochromic pigment material to the melt pump; 
 providing a volume of the molten mixture to the spinneret with the melt pump; and 
 operating the spinneret to coat an electrically conductive core with an inner coating layer of the first molten mixture to provide a color-changing fiber; 
 coating the color-changing fiber with a second molten mixture to form an outer coating layer over the inner coating layer, wherein the outer coating layer is configured to activate at a first temperature threshold and the inner coating layer is configured to activate at a second temperature threshold that is higher than the first temperature threshold, wherein a first temperature at or above the first temperature threshold is configured to cause the outer layer to transition from an opaque state to an at least partially transparent state to expose the inner layer, and wherein a second temperature at or above the second temperature threshold is configured to cause the inner layer to transition from a first opaque state to at least one of a second, different opaque state or a third, at least partially transparent state; 
 arranging the plurality of color-changing fibers to provide at least a portion of a color-changing product; and 
 ultrasonically welding at least a sub-portion of the portion to form a weld that electrically connects the electrically conductive core of two or more of the plurality of color-changing fibers through the coatings thereof. 
 
 
     
     
       16. The method of  claim 15 , wherein at least one of the plurality of color-changing fibers is different from the others of the plurality of color-changing fibers. 
     
     
       17. The method of  claim 15 , wherein arranging the plurality of color-changing fibers to provide at least the portion of the color-changing product includes:
 (i) weaving or knitting the plurality color-changing fibers to form at least a portion of a fabric of the color-changing product; or 
 (ii) embroidering the plurality of color-changing fibers into the fabric of the color-changing product.